• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.11a
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• pp.138-138
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• 2004

• Investigative Magnetic Resonance Imaging
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• v.25 no.4
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• pp.218-228
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• 2021

Due to their high degree of freedom to transfer and acquire light, fiber optics can be used in the presence of strong magnetic fields. Hence, optical sensing and imaging based on fiber optics can be integrated with magnetic resonance imaging (MRI) diagnostic systems to acquire valuable information on biological tissues and organs based on a magnetic field. In this article, we explored the combination of MRI and optical sensing/imaging techniques by classifying them into the following topics: 1) functional near-infrared spectroscopy with functional MRI for brain studies and brain disease diagnoses, 2) integration of fiber-optic molecular imaging and optogenetic stimulation with MRI, and 3) optical therapeutic applications with an MRI guidance system. Through these investigations, we believe that a combination of MRI and optical sensing/imaging techniques can be employed as both research methods for multidisciplinary studies and clinical diagnostic/therapeutic devices.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.10
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• pp.5130-5143
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• 2019

Football (soccer) is one of the most popular sports in the world. A huge number of people watch live football matches by TV or Internet. A football match takes 90 minutes, but viewers may only want to watch a few highlights to save their time. As far as we know, there is no such a product that can be put into use to achieve intelligent highlight extraction from live football matches. In this paper, we propose an intelligent editing system for live football matches. Our system can automatically extract a series of highlights, such as goal, shoot, corner kick, red yellow card and the appearance of star players, from the live stream of a football match. Our system has been integrated into live streaming platforms during the 2018 FIFA World Cup and performed fairly well.

• Current Optics and Photonics
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• v.3 no.4
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• pp.298-303
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• 2019

We propose a photonic quasi-crystal fiber (PQF) for supporting up to 14 orbital angular momentum (OAM) modes with low and ultra-flat dispersion characteristics over the C+L bands. The designed PQF which consists of a large hollow center and quasi structural small air holes in the clad region exhibits low confinement losses and a large effective index separation (>$10^{-4}$) between the vector modes. This proposed fiber could potentially be exploited for mode division multiplexing and other OAM mode applications in fibers.

• Korean Journal of Optics and Photonics
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• v.18 no.3
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• pp.196-201
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• 2007

A theoretical study of Brillouin optical time domain analysis (BOTDA) using two pulse lasers is performed. Even though a point detection is made for a pump pulse period, the dynamic range of BOTDA using two pulse lasers is approximately 5 dB more than that of a pulse and a CW laser when the fiber length is 140 km and the Stokes power is 1 mW.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.996-999
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• 1996

This paper introduces prototype design of 765kV Substation control system based on fiber optics LAN and distributed network protocol. Two major important facts, immunity of any surge which frequently occurs in Ultra High Voltage Substation and the most suitable communication protocol for substation control system, are considered on the system design conception. To meet the first fact, use of fiber optics cable and isolation transformer are considered, and to satisfy the second fact, DNP3.0(Distributed Network Protocol) which is IEC870-5 compatible is adopted.

• Journal of the Society of Naval Architects of Korea
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• v.36 no.3
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• pp.22-28
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• 1999

Flow measurements on the propeller plane of a 180,000 TDW Bulk Carrier model are carried out using a 3D fiber optics LDV at a towing tank. Mean velocities are successfully obtained. The turbulence characteristics such as Reynolds stresses, skewnesses, and flatnesses, are also investigated. However, those turbulence characteristics may include some errors due to the characteristics of the towing-tank experiments.

• Proceedings of the Korean Fiber Society Conference
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• 2007.11a
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• pp.523-524
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• 2007

• Journal of the Optical Society of Korea
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• v.13 no.1
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• pp.33-36
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• 2009

Laser ablation with femtosecond lasers is highly promising for microfabrication of materials. Also, the high peak power of femtosecond lasers could induce a multiphoton absorption to ablate transparent materials. Similar results have also been were obtained in the case of optical fibers. In this paper, we present our experimental results of femtosecond laser microstructuring of optical fiber and its applications to microelectronic components and fiber optic devices. Finally, we directly produced micro holes with femtosecond laser pulses in a single step by moving an optical fiber in a preprogrammed structure. When water was introduced into a hole drilled from the bottom surface of the optical fiber, the effects of blocking and redeposition of ablated material were greatly reduced and the aspect ratio of the depth of the hole was increased. We have presented circular and rectangular-shaped holes in optical fiber.

• Korean Journal of Optics and Photonics
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• v.16 no.6
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• pp.490-493
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• 2005

We have experimentally studied supercontinuum generation in a photonic crystal fiber as a function of pump wavelength and intensity with 100 fs pulsewidth. A supercontinuum over 750 nm spectral width with amplitude variation less than 10 dB has been achieved. It was generated by coupling femtosecond pulses from a mode-locked Ti:Sapphire laser into a 2 m long photonic crystal fiber. Adjusting the parameters of the pump source, it was also possible to control different spectral features of the supercontinuum radiation.